Compressor or other engine



Ang. 16, 193s.

COMPRESSOR 0R OTHER' ENGINE Fild sept. 15, 193e Vs sheets-sheet 1 o. LUTZ 2,127,126

Aug. 16, 193s. o, LUTZ 2,127,126

` COMPRESSOR OR OTHERENGINE Filed Sept. 15, 195e s sheets-sheet 2 L 'lllllLl/(lla 0 .La van for ug. 16, 1938. o. LUTZ COMPRESSOR 0E OTHER ENGINE Filed Sept. l5, 1956 5 Sheets-Sheet 3 Patented Aug. 16, 1938 UNITED STATES COMPRESSOR OR OTHER ENGINE Otto Lutz, Fellbach, near Stuttgart, Germany Application September 15, 1936, Serial No. 100,856 In Germany September 18, 1935 7 Claims.

My invention relates to compressors or other engines and more particularly to means for compressing gases and for transforming gas pressure into kinetic energy.

In apparatus according to my invention a plurality of walls extend across a working chamber and these walls in moving in the chamber relative to each other continuously andl alternately increase and diminish the volume of the spaces enclosed between them, whereby the apparatus is enabled to either compress and convey gases or to transform energies stored in a compressed gas into pressure acting on another gasor to convert heat energy into mechanical energy.

In the drawings aixed to this specification and forming part thereof several embodiments of my invention are illustrated diagrammatically by way of example.

In the drawings- Fig. 1 is an axial section of one form of such an apparatus, while Fig. 2 is a cross-section on the line 2--2 in Fig. 1.

Fig. 3 is a perspective View of the movable parts of a second modification, while Fig. 4 is an axial section illustrating a modified form of part of the first modification (Figs. l and 2).

Fig. 5 is a showing, similar to that in Fig. 4, of a fourth modification.

Fig. 6 is a perspective View, similar to that of Fig. 3, of a fifth modification and Fig. 7 is a perspective view showing a detail.

Fig. 8 is an axial section drawn to a larger a scale, of a detail on the right hand side of Fig. 6.

Fig. 9 is a perspective view, partly in axial section and also drawn to a larger scale, of a different form of driving means.

Fig. 10 is an elevation, partly in axial section, of a modified form similar to that in Fig. 9.

Referring to the drawings and first to Figs. l and 2, f is the substantially cylindrical casing of the compressor or engine and b and h are covers closing same. g is a hollow shaft supported in bearings formed in the covers b, h for rotation, a being the driving wheel mounted on the projecting end of shaft g. e is a partition extending obliquely across the middle portion of the shaft and separating same in two parts. d1, d2 are cam plates formed on or fixed to the shaft g near its ends. The cam plate d1 is formed with a gas inlet E, cam plate d2 with a gas outlet A. Gas entering the left hand end of the hollow shaft in the direction of the arrow B will thus enter through E and escape through A, the inlet and outlet openings being arranged in staggered relation.

Between the two cam plates d1 and d2 are arranged for free axial movement relative to the shaft g four helical walls c1, c2, c3, c4, each wall extending through an angle of 360 so as to form a single-thread screw.

The two aligned ends of each helical wall are in contact with the two cam plates d1, d2 and the adjoining ends of the four helical walls are stag- 5 gered by as shown in Fig. 2. The two ends of each helical wall are coupled by means of pins 11,1, n2, n3, n4, respectively, with slides m1, m2, m3, m4, respectively, mounted and guided in slots 21, z2, z3, 24 formed in the inner wall of the l51,0 cylindrical casing f.

The operation of this device is as follows:

When the shaft g is rotated, the cam plates d1 and d2 will force the four helical walls c1, c2, c3, c4 to reciprocate on and relative to the shaft )15 in axial direction, being axially guided by the slides m1 and slots 21 According to the angle enclosed between the cam plates and the shaft the movements of the four walls will take place in staggered relation. When wall c1 arrives 20 at the left hand end of the casing shown in Fig.

1, the wall c3 will reach the right hand end, while the walls c2 and c4 will at that moment assume intermediate positions. Since the four walls enclose between them helical spaces and owing tothe particular relative movements, which they go through, the distance between the surfaces of each pair of adjoining walls will increase during the first half and decrease during the second half of each revolution of the shaft and in conse- 30 quence of this permanently occurring change of volume of the helical spaces between the walls a gas passing through between them will have its volume changed also. Gas entering in the direction of the arrow B, while flowing in the space ...35 between two adjoining helical walls c1, c2 will be compressed while the shaft rotates through an angle of", since the two walls will then approach each other and the gas will thus escape through the outlet A under a higher pressurenl() Obviously, on the other hand the increase in volurne of the spaces enclosed between each pair of walls during the second half of a revolution of the shaft, will create a pressure below normal, in other words a suction effect in the space enclosed 45 between these walls, so that gas will constantly be sucked in through' the inlet E and expelled under pressure through the outlet A.

In the modification illustrated in Figs. 1 and 2 all contiguous surfaces can be turned on the lathe 50 or ground at lowcost in the simplest manner and the efficiency of this apparatus will therefore be particularly great.

Fig. 3 illustrates in a highly diagrammatic mariner a modified form of the device shown in Fig. 1. Here each of the helical walls extends through ari angle of 720, thus forming a double-thread screw,

`the four walls being shifted forth and back in alternation on the shaft by the two cam plates.

As shown in Fig. 4, the inlet opening E (and 60 similarly also the outlet opening) may be formed in the wall of the hollow shaft.

Fig. 5 illustrates the case, where the cam plates d are fixed to the casing fa, being thus secured against rotation, while the helical walls ce are made to rotate with the shaft. Here the inlet opening E (and also the outlet opening) are formed in the casing wall.

In the modied form of Fig. 6, which, as far as the helical walls are concerned resembles that shown in Fig. 3, the ends of the helical walls or pistons c are formed with guide pieces `e1 of segment shape, which reciprocate on the shaft in sliding contact with each other. The ends of the helical walls or pistons are secured against bending and circumferential stresses and can be machined in a particularly simple manner, since the four helical pistons may be assembled by themselves without being first fitted in the casing and on the shaft and can then be turned down to the corresponding diameters.

Friction between the guide segments el` can be reduced by inserting between them antifrictional guide members such as balls o, which may be guided in split tubesi (Figs. 6, 7 and 8).

In the modifications hitherto described the helical walls or pistons are acted upon for axial reciprocation at their ends only, where they are in contact with the cam plates, which thus exert a push on the walls. I may, however, also provide for a double-sided drive of the helical walls or pistons, as shown in Figs. 9 and l0.

In the modication of Fig. 9 rollers lc are mounted in the ends y of the helical walls, these rollers projecting between pairs of cam members w fixed to the shaft o.

As shown in Fig. 10 pairs of rollers t may be mounted in the ends s of the helical walls and a cam plate r may extend into the interstice between the two rollers, so that here also the helical walls are acted upon by the cam plates in both directions. The pistons may be carried along by the shaft by means of slidingor rolling-contact guides. Alternatively the shaft may be formed with cam grooves in which the pistons are guided or the ends of the shaft may be formed with axial teeth meshing with internal rows of teeth formed Aon the piston ends.

Obviously, in the latter arrangements according to Figs. 9 and 10 a single cam plate will prove sucient, which may be arranged either at the suction or at the pressure end of the device. I however prefer to provide two cam plates, more especially in the case where'the helical walls or pistons are required to take up higher pressures. For if each helical piston is acted upon and guided at either end, the distance between the ends of a piston will remain constant even if pressures acting on the helical walls would tend to deform them. By this arrangement the bending and circumferentially acting stresses are also reduced and the mechanical pressure is distributed onto two driving parts (cam plates).

While, in all the modifications illustrated in the drawings, I have shown devices provided with four helical pistons, obviously any number of such pistons may be provided in accordance with the degree of compression desired and the number of strokes which the cam plates are required to produce. In Fig. 10, for example, a two-stroke cam plate T is shown.

The helical pistons may be formed withv a single or multiple thread and also with 5/1 or 1% threads etc. The pistons may also be guided and acted upon by annular segments at points intermediate their ends.

The output of devices of this'kind is a very favorable one. The helical walls act as pistons, the effective surface of which, when more than one thread is provided, corresponds to the larger annular surface between the casing wall and the shaft. Apart therefrom each piston conveys gas on each stroke, so that although the length of strokes may be small, the apparatus can easily be designed to convey up to the double of the volume enclosed between the shaft and the casing Wall per revolution of the shaft, and in the case of multiple thread cam plates a multiple thereof.

Since the size of an apparatus of this kind may be small, the ratio of volume conveyed per revolution to the size of the apparatus is extremely favorable. the helical pistons execute only short strokes and consequently high numbers of revolution can be attained. A perfect` mass equilibrium in axial direction can easily be attained.

Since the parts, from which the apparatus is built up. are of simple forms, they can easily be calculated for different stresses and their weight can thus be made as low as possible. The apparatus is therefore particularly suitable for use in portable units and either as a conveyor (blower, pump, compressor etc.) or as a power engine or also as a combination of both.

I wish it to be understood that I do not desire to be limited to the exact details of construction shown and described, forobvious modifications will occur to a person skilled in the art.

I claim:

1. A device of the kind described, comprising in combination, a casing member enclosing a cylindrical chamber, a rotatable shaft member extending axially through said chamber, a plurality of overlapping, helical, pistons surrounding said shaft member, said pistons being guided for axial motion relative to both of said members and for rotation relative to one of said members, a' cam plate structure fixed to said one of said members and contacting said pistons to force them to reciprocate axially relative to said chamber as said shaft member is rotated, an inlet passage successively communicating with the respective spaces between adjacent pistons, and an outlet passage also successively communicating with said spaces after they have been cut oiffrorn communication with said inlet passage. 2. 'Ihe combination of claim 1, in which the helical pistons loosely surround the shaft member. 3. The combination of claim 1, in which the shaft member is hollow, one part of said shaft member being formed with an inlet registering with the inlet of said casing member, while the other part is formed with an outlet registering with the outlet of said casing member.

4. The combination of claim 1, in which slides reciprocable in axially extending slots of the casing member serve for guiding the helical pistons.

segments are provided on adjoining endsyof the helical piston, said segments closing the chamber and being axially guided.

6. The combination of claim 1, in which a double acting cam plate structure is provided.l

7. The combination of claim 1, in which a pair of cam discs is provided,

1 QTTO LUTZ.

The mass forces are low, since 5. The combination of claim 1, in which guide 

